Mei Li

Mixed rare earth concentrate leaching with HCl–AlCl3 solution

A method of Baotou mixed rare earth concentrate leaching was investigated. According to the principle of complex leaching, the quadratic orthogonal regression experiment was used to investigate effect of six factors. An optimal condition of low energy and environment friendly was determined as follows: HCl acidity is 4xa0mol·L−1, AlCl3 concentration is 2xa0mol·L−1, reaction temperature is 85xa0°C, reaction time is 90xa0min, liquid to solid ratio is 35xa0ml·g−1, and stirring speed is 100xa0r·min−1. According to this condition, the leaching ratio of mixed rare earth concentrate is 76.5xa0%. The analyses of X-ray diffraction shows that bastnasite disappears, and the main peaks of filter residue is monazite and cheralite after leaching of HCl–AlCl3 solution. The result indicates that REFCO3 of the mixed rare earth concentrate can be dissolved, but REPO4 remains in the leaching residue. This method provides a way to separate and extract rare earth.